Cathode-ray tube modulator



Aug. 1, 1950 E. LABIN ETAL 2,516,386

omens-RAY was uonum oa Filed Sept. 11, 1945 4 Sheets-Sheet 1 ii I i H Ya mmiofiou wqofiwu h 3 N.-. v

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Aug. 1, 1950 E. LABIN ETAL CATHODE-RAY TUBE uonum'on 4 Sheets-Sheet 2 Filed Sept. 11, 1945 INVENTORS EMILE LAB/IV DONALD a. 67/56 ATWR/EY 1950 r E. LABIN ETAL 2,516,886

CATHODE-RAY TUBE MODULATOR Filed Sept. 11, 1945 4 Sheets-Sheet 4 A TIDE/VF) i ma i, 1950 V GATHODE-BAY TUBE MODULATOR Emile Labin, New York, and Donald D. Grieg,

Forest Hills, N. Y., aasignors to Federal Telephone and Radio Corporation, New York, N. Y.,

' acorpo' ration oi Delaware Application September 11, 1945, Serial No. 615,538

23 Claims.

This invention relates to an electron beam apparatus. More particularly it relai'es to a cathode ray tube ior directly convertins variable continuous energy waves into provariable time spaced pulses. Such a tube, ior example; may be used in electrical muiti signal transmission systems emplowing time-modulated pulses as described in our application, for "Multichannel Pulse Module Serial No. 567,414, filed De- 9. 1944, now Patent No. 2,495,738, granted January 31, 1950, of which this invention is an improvement.

It is an object of this invention to convert continnom energy variations into directly proportional time-displaced pulses in a simple, accurate, and efiective manner.

Another object is to convert such energy variations into time-displaced pulse variations by means oi a cathode ray tube.

Another object is to compensate for the distortion due to special geometry of such a tube in order to obtain a direct linear relationship between the amount of such energy variation and the time displacement of corresponding pulses.

Another object is to provide means to decrease the amount of energy required to produce a response in the tube and to increase the functional accuracy of such a cathode ray tube.

Another object is to produce pulses of subshmtially eq al duration.

Another object is to decrease the distortion obtained in the type of cathode ray tube disclosed in the above-mentioned copending application.

Another object is to improve and simplify multichannel transmission systems.

Another object is to provide an improved modulator device.

Another object is to provide a multichannel transmitter which requires less equipment, fewer tubes, and is more economical to build and tain than prior multichannel transmitters. Another object is to prevent cross-talk in multichannel transmission systems.

Still other objects will appear from time to time in the description which follows.

One of the features of this invention is the employment of a cathode ray tube or other electron beam-producing apparatus having means to cause the beam to sweep through a given mt, together with a series of special electrodes which coact with the beam and a target arrangement to produce time displaced pulses. When energy, such as a signal is applied to any one of the special electrodes in the tube, the beam is deflected from the path of its normal sweep movement by an amount corresponding to the amount of this energy. each electrode may comprise a separate signal channel. The target assembly is arranged to present a plurality of electron-responsive areas, one for each of said special electrodes. These areas are arranged in series relation so as to be traversed in succession by the beam during its sweep movement. The areas when traversed by the beam produce pulse flow of electrical energy by secondary emission. To eiiect time modulation of the pulse energy, the target assembly comprises a shielding means having a series of long and narrow apertures or slots disposed at acute angles to the direction of the beam deflection. The sweep of the beam traverses the beam responsive area behind the shielding means through the apertures sooner or later in time depending upon the amount of energy or signal applied to the special electrodes which controls deflection of the beam. Thus the output pulse energy for each signal is time displaced relative to an average time position according to' the instantaneous value of the modulating signal.

In a cathode ray tube wherein the sweep circuit causes the electron beam to rotate around the tube-at a constant angular velocity and the deflecting electrodes for the beam deflect it radially toward and away from the geometric center of the tube, there is a difference in the circumferential velocity of the end of the beam depending upon its deflection. In order to compensate for this difference and the tube geometry so that the beam will traverse the beam responsive area through the slot in a direct timespace relationship to the amount of energy causing the deflection, the aperture must be properly shaped and/or positioned across the path of the end of the beam. The theoretical line across the target area which will produce time spaced pulses directly proportional to the energy for radially deflecting the beam, may be mathematically calculated. This line is not a straight line, but a, curved one which in some cases may be more complex than a simple are.

In calculating the shape and position of this line, both the circumferential movement and the radial deflection movement of the beam are considered. Thus, to directly and linearly time-displace the variations in deflecting energy with the motions of the beam, the target area or aperture, should be positioned and spaced to cover substantially all of this calculated curved line. Two methods for doing this are: (1) to provide a curved aperture to uniformally bracket the theoretical line; and (2) to use a straight and narrow slot so positioned substantially as to cover and bracket the curved line.

The long and narrow apertures include end portions disposed parallel to the direction of the signal beam deflection, i. e., substantially radial, so as to provide maximum limits of pulse displacement. This prevents break through from one channel to the next when signals of unusually high value occur.

The. target assembly, comprising the apertures and/or the beam responsive means, may be positioned substantially perpendicular to the beam, such as by forming it out of obtuse conical plates.

The electron beam may be commutated into beam segments, one corresponding to each of the deflection plates connected to each signal channel. This may be accomplished by either providing a commutating plate with apertures through which the beam travels, or by means of commutation keying of the grid, on control electrodes of the cathode ray tube whereby the beam is divided into segments for modulating treatment by the signals to be transmitted. This feature of providing individual beam segments is important in avoiding cross-talk that may otherwise occur if the deflection produced by signals of one channel were permitted to be carried over by the beam to the next deflecting zone of the adjacent channel.

The deflecting electrodes may be extended a considerable distance parallel to and along the path of each beam segment so that a lower voltage may be used to produce a given deflection oi the beam. This in turn reduces the acceleration of the electrons in the beam so that they will be deflected more by smaller changes in en-.

ergy in the signal. Such electrodes may be cylindrical, frusto-conical, or both, and are preferably flared at their target ends to permit free deflection of the beam passing between them.

Another feature of this invention for use in deflecting the beam segments in response to signal energy comprises varying the acceleration of each beam segment in accordance with the signal energy, then passing the beam through a constant deflecting potential.

The above and other objects and features of the invention will become more clear upon consideration of the following detailed description to be read in connection with the accompanying drawings, in which:

Fig. 1 is a diagrammatical illustration of a multichannel pulse time modulator according to the principles of this invention;

Fig. 2 is a geometric diagram of a theoretical time-space deflection line on the target and relative to the shape and position of a target area of one embodiment of this invention;

Fig. 3 is a graphic representation of the time modulated operation and the shape of the arcuate target area of another embodiment of this invention;

Fig. 4 is a graphical illustration showing a period of multichannel pulses and of control wave employed in the modulator;

Fig. 5 is a longitudinal section of'a cathode ray tube of a further embodiment of this invention; and

Fig. 6 is a diagrammatic showing of still another embodiment of the modulator of this invention.

5 pulses is shown in graph 12 of Fig. 4, the pulses of signal channels I to II being of a given pulse width and the synchronizing pulses l2 being of a greater pulse width, whereby the latter can be separated from the signal channel pulses at the receiver by a suitable pulse with discriminator.

While this system is shown for 12 channels in all, it will be understood that a great many more channels may be provided, (for example, such as 24 channels) the number per modulator tube becharacter of sweep movement selected from the beam, the maximum time displacement per channel, the guard intervals between pulses of adjacent channels and the widths of the pulses.

Referring more particularly to Fig. 1, a modulator is shown in the form of a cathode ray tube l3. While thisform of modulator is shown to illustrate the invention, it will be understood that other forms of electron beam producing arrangements may be employed; also it will be understood that the tube illustrations in other figures are purposely exaggerated as to the relative proportions and spacing of elements to assist in explaining the principles of the invention, and therefore the illustrations generally do not represent the ultimate proportions desired for commercial embodiments.

The tube l2 contains electron beam producing elements ll, II and I2, preferably of the character capable of producing a fine beam of electrons. The beam of electrons is caused to have a sweep movement by means of horizontal and vertical (x-axis and u-axis) deflecting plates H, II and I0, 20. The sweep movement chosen for the purpose of illustrating the present invention is circular and the deflecting waves for producing this sweep movement are obtained from an oscillator 2i and a phaser 22. The control waves obtained from phaser 22 are represented in graph a of Fig. 4 by sine waves 23 and 24, separated in phase by 90. Sweep movements other than circular may be used, for example, a sweep pattern such as used in television scanning may be employed.

A commutator plate 25 having a series of apertures 28, 21, etc., arranged in a circular manner divides the beam during its sweep movement into segments. The apertures for the signal channels are preferably shaped in the form of sectors, the 55 sides thereof being defined by radii of the plate 25. This shape, however, is not essential except where a maximum number of channels is required. The aperture 22 for the synchronizing channel need not be of this shape even where a 0 maximum number of channels L desired; it may instead be of narrow rectangular form.

To effect signal deflection of the beam segments, 9. frusto-conical electrode 29 is provided with a series of small leaf electrodes 30, II, etc.,

05 disposed in series relation about the edge of the electrode 29. The electrodes 3., ii are arranged so that the corresponding beam segments passed by apertures 2, 21, etc., occur between them and the central electrode 22. The signal is applied to the small electrodes; the electrode ll being connected to the input circuit of channel I as indicated at 32. The input signal is preferably stepped up by transformer 22a, before application to the electrode.

II The target assembly with which the electrons ing limited largely by the size of the tube, the

of the beam cooperate to produce pulse energy flow comprises a shielding. or modulator plate 33 and an electron responsive area or secondary electron emission ring 34. The potential oi. the plate 33 is maintained higher than that on the ring 34 so that when electrons impinge upon the ring 34, the ring emits electrons which flow to the plate 33. The plate 33 is provided with long and narrow slots 38, 38, etc., one for each channel. for' passage of the beam for impingement upon the area of ring 34. The central portion oi the slots for the signal channels are preferably disposed at an acute angle with respect to the direction of signal deflection produced by the potential difierences between the electrodes 34, 3|, etc., and central electrode 2!. The end portions 7 of the slots, however, are disposed parallel to the direction of signal deflection. The slot 31 for the synchronizing channel is disposed parallel to the direction of signal deflection. This relationship oi the slots of plate 33 and the beam sweep movement is shown on a larger scale in Fig. 2. 7

Referring to Fig. 2, a segmented beam of electrons is shown by dotted line 34 passing between the deflection electrodes 23 and 33. This beam 33 may be deflected from its original arcuate path 33, across the sector 0 of a given channel target area on the plate 33 through an angle between the longer arcuate path 43 and the shorter arcuate path II, respectively. Since the angular velocity of the beam 38 is constant. the velocity of the end of the beam along arc 40 would be much greater than along arc 4| or even an intermediate are 39. Thus, a straight slot proportioned along line 42 from the lower left corner of the sector channel to the upper right corner thereof, would not time space impulses onto the beam responsive means (not shown in Fig. 2) directly proportional to the radial deflection of the beam 33. The path of the mathematically calculated directly proportional time-space deflection line across the channel sector is shown as arouate line 43. Thus. in order to position a straight long and narrow slot of given width, such as aperture or slot 35, to cover substantially the line 43, it must be moved both a little to the left and at an angle to the line A! as shown.

Another way of forming a target area or slot which will cover the theoretical line 43 is to make the aperture arcuate and similar to that of the line 43 such as that shown in Fig. 3. The dotted line 44 in Fig. 3 represents the sweep path of the beam 38 in the absence of signal modulation. It will be noted that this path traverses the center of the central portion 46 of the arcuate aperture 46. The beam for this normal sweep movement causes secondary emission of electrons from plate 34, thereby producing a pulse flow of energy substantially as indicated at 41.

Assume now that a signal occurs on electrode 30 of a positive value such as to cause a deflection of the beam 33 to the path indicated at 43. This will produce a pulse flow displaced from the pulse timing at 41 as indicated at 49. The radially outward extended portion II of the slot 46 is provided as hereinbetore stated to limit the time displacement for exceptionally large signal values. cated at 49 will occur for any displacement of the beam along the length of portion 53. If the aperture 46 were terminated at the end of the central portion 45 no output pulse would be obtained for a signal causing deflection beyond such end.

r by controlling the amplitude of the deflectili'g' The output pulse such as indi- Foranegativeswingofsignsionelech-ode 23 thebeamuwillbeshittedtoapathinwardof the path 44. Such a negative swing may he represented by the path 5|, the corresponding output pulse being represented at 52. The radial portion 53 of the aperture 46 provides a maximum negative displacement for the pulse similarly as in the case of the outward end portion 50. The aperture 31 for the synchronizing channelisshowninFig. 3 to bearadialnarrowslot, although it may take the form of a small square aperture since for the synchronizing channel no deflecting potential need be provided. The aperture 3'! preferably is elongated as shown to accommodate any offset bias that may be normally imposed upon the system, such for example as waves supplied to electrodes (I to 33.

Both the apertures 35 (previously mentioned) and 46 may be tapered slightly wider at their outer ends along lines 43 and 48 than at their inner end along lines 4i and BI, respectively, to compensate for the diiference in circumferential velocity of the beam along these lines and thereby produce impulse of equal duration for any deflection.

Referring back to Fig. l, the potentials applied to the different elements of tube i3 are indicated. The elements ll. 20, 25. 23 and 33 are all provided with the same high voltage potential as indicated at 54. The control grid I5 is shown to be provided with a high negative voltage by connection 55 while the cathode element i4 is provided with a less negative voltage by the interposition of a, resistor 56. The beam shaping or focusing element i6 is provided with a more positive potential than the cathode it by means of resistors 51 and 58. The anode target ring 34 is provided with a less positive potential than the modulating plate 33 by means of the interposed resistors 53, 59 and Gil. The output of the circuit elements 33, 34 is applied to a cathode follower 6|, the output energy of which may be applied to the usual carrier frequency modulater for transmission. It will be noted here that this output circuit is independent of the electron beam circuit. This is of advantage because the secondary emission function of the elements 33 and 34 is in effect an amplification of the signal energy. For example, the targets may be made a part of the beam circuit whereby the beam current controls the output of the tube. In such cases, however, the beam current controls and in order to get desired amplification amplifiers are required.

From the foregoing description it can be readily seen that the combination of the apertures or slots of the modulation plate 33 and the anode ring 34 provide the pulse generation, and the sequential distribution shape and position of the apertures provide the necessary delay or phase difference between the'pulses of adjacent channels. The deflection system 23, 33, 3|, in conjunction with the shape of the apertures of the modulator plate 33 provide the modulation translation of signal increments from amplitude variations into time displacements of pulses.

Further, the shape and position of the apertures of plate 33 allows modulation limitation for each channel. The width of the apertures of plate 33 determines the width or duration of the channel and synchronizing pulses, the aperture for the synchronizing channel being wider, distinguishes the-synchronizing pulses from the signal channel pulses. Finally the combinations of the modulator plate 33 and the anode ring 34 provides for the mixing of the channel and synchronizing pulses into a single train of pulses for transmission. Such a train of pulses is shown in graph b of Fig. 4, the period oi. which corresponds to the period oi. the beam control waves shown in graph a.

Referring now to Fig. 5, the location of the elements of tube l3 shown in Fig. 1 are all proportionally placed and the respective shape and form of the electrodes 29 and 30 are more clearly shown. The center and major electrodes 29 comprise two axially adjacent frusto-cones having spaced around it the minor electrodes 30, 3|, etc., formed of strips bent near their center so as to be spaced a greater distance from the electrode 29 at the outgoing end of the beam 38 than at the ingoing end for that beam. This particular structure, however, is not limiting. Any similar structure which permits free deflection oi the beam 38 as well as paralleling the beam for a comparatively long distance may be found advantageous and desirable.

Either or both the modulating plate 33 and secondary electron emission ring 34 shown in Fig. 1 may be replaced by the obtuse conically shaped plates 62 and 63 (shown in Fig. 5) respectively mounted perpendicularly to the target end of the electrode beam 38. The use of conically shaped plates 62 and 63 eliminates the factor of the secant of the angle a, between the axis of the tube and the deflection due to the sweep movement of the beam 38, from the calculation of the theoretical time space deflection line 43.

In Fig. 6 is shown still another alternative form of modulator. The modulator tube i312 differs from the tube l3 of Fig. l in that the grid is keyed according to a commutating control wave which replaces the commutator plate 25 used in the tube of Fig. 1, and the signal deflecting arrangement is replaced by a signal acceleration-deflection system. The commutation control of the grid 15 keys the beam on and off according to the channel timing desired. This is accomplished by applying the base wave of oscillator 2| to a multiplier 64 to obtain the proper channel frequency. The output wave of multiplier 64 is phased at 65 and applied to a shaper 66 which may be a multivibrator or other wave shaping means capable of transforming a sine wave into a substantially rectangular wave form. The rectangular wave thus obtained is applied to the grid I5 which is normally biased to cut off.

The signal acceleration-deflection of the beam is effected by first providing a cylindrical electrode 61 spaced from an annular electrode '68 between which a potential difference is applied as indicated at 69. The potential difference between these two elements provides a constant deflection force for the beam passing therebetween. Each signal channel is provided with a hollow cylindrical element, such as indicated at 10 for channel I, through which a beam segment passes, once for each sweep cycle of the beam. It will be understood of course that the sweep movement will be synchronized with the keying operation so that a beam segment occurs in proper time relation for each of the hollow cylindrical electrodes of the several signal channels. As the beam segment flows through the hollow cylinder 10 the potential applied thereto will accelerate or decelerate the electrons according to the value of the signal applied. A given positive bias may be applied as indicated at H for each channel so that the positive and negative values of signals will cause the electrons of the beam to accelerate and decelerate proportionately. This change in acceleration of the beam of electrons coacts with the constant deflecting potential of electrodes 61 and 39 to vary the amount of deflection oi. the beam relative to the apertures of the modulator plate 33. It will be clear that this variation is effected in accordance with the signal and that the output pulse is time displaced in proportion to the signal value.

Another modification shown in Fig. 6 is that the two electrodes 61 and 63 are cylindrical in shape and that they produce a different shaped pattern on the plate 33 than that previously disclosed. In this case the theoretical curved time spaced deflection line on the target area is in the shape of an 8. so S-shaped apertures 12 are shown on the plate 33 in Fig. 6. However, instead of the s-shaped apertures, straight slots may be used which are positioned to cover substantially this theoretical line as in the embodiment shown in Fig. 2.

. It will be understood that the keyin oi! the beam by means of the grid I5 may also be applied to the system shown in Fig. 1 in place of the commutator plate 25 shown therein.

- Further it will be understood that any one or more of' the different features disclosed in the different modifications may be employed in any one or several different cathode ray tubes. Also.

many additional variations and arrangements of the tube elements and associated circuits are possible without departing from the invention. For example, the beam may be shaped prior to its deflection, thereby doing away with special shaped fiat apertures in plate 33, as is more fully described in our copending application referred to above.

It is accordingly stressed that the different embodiments herein shown and described are intended for illustration purposes only and not as a limitation on the scope of the invention as set forth in the objects and the accompanying claims.

We claim:

1. A cathode ray tube comprising: means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, means to divide the beam into a successive plurality of segments with respect to said sweep movement. a deflecting electrode arranged along the path of each said beam segment to control radial deflection of that beam segment, separate means for applying energy to each said electrode, means responsive to said beam segment, and shielding means positioned between said beam responsive means and said deflecting electrodes, said shielding means having long and narrow arcuate apertures therein corresponding to each beam segment through which said beam segments pass, said apertures being shaped and positioned to cover substantially the curved theoretical time-shaped deflection line calculated to compensate for the different circumferential sweep velocities of said beam segments, so that the energy of each beam segment is transmitted successively to said beam responsive means in time spaced relationship directly proportional to the amount of energy applied to said'deflecting electrodes whereby distortion of this proportion due to said different velocities of said beam segments is prevented.

2. A cathode ray tube comprising: means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, means to divide the beam into a successive plurality of 9 segments with respect to said sweep movement, a deflecting electrode arranged along the path of each said beam segments to control the radial deflection of that beam segment, separate means tor-applying energy to each of said electrodes, means responsive to said beam segments, and a shielding means positioned between said beam responsive means and said deflecting electrodes, said shielding means having apertures therein corresponding to each beam segment through which that beam segment passes, each of said apertures being long and narrow and disposed at an acute angle to the radius through the center of said tube and spaced slightly in the opposite direction from the sweep movement of said beam segment whereby the theoretical time spaced deflection curved line for traverse by the end oi said beam segment is substantially bracketed so that the energy from each said beam segment is transmitted successively to said beam responsive means in a time spaced relationship substantially directly proportional to the amount of energy applied to said deflecting electrodes.

3. A cathode ray tube comprising: means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, means to divide the beam into a successive plurality of segments with respect to said sweep movement, means arranged along the path of each said beam segment to control the radial deflection of that beam segment, separate means for applying energy to each of said last mentioned beams, means responsive to said beam segment, and shielding means positioned between said beam responsive means and said deflecting means, said shielding means having apertures therein through which said beam segments pass, said apertures being so shaped and so positioned with respect to the motion of said beam segments to transmit energy in each beam segment successively to said beam responsive means in a time spaced relationship substantially directly proportional to the amount of energy applied to said deflecting means, said deflecting means including a major electrode disposed centrally of the sweep path of said beam and a plurality of minor electrodes disposed in sequential relation along the sweep path of each said beam segment and spaced from said major electrode; and said beam responsive means having the form of an obtuse cone positioned axially of said tube, the conical sides of which are substantially perpendicular to said beam as it is defiected around the tube.

4. A cathode ray tube comprising: means to produce a beam of electrons. means to cause said beam to have a circular sweep movement, means to divide the beam into a successive plurality of segments with respect to said sweep movement, means arranged along the path of each said beam segment to control the radial deflection of that beam segment, separate means for applying energy to each of said last mentioned means, and means responsive to said beam segments; said means for controlling the deflection of said beam segments including a major electrode disposed centrally of the sweep path of said beam and a plurality of minor electrodes disposed in sequential relation along the sweep path of each said beam segment and spaced from said major electrade; and said beam responsive means having i0 produce a beam of electrons, means to cause said beam to have a circular sweep movement, means to divide the beam into a successive pinrality oi segments with respect to said sweep movement, means arranged along the path of each said beam segment to control the radial deflection of that beam segment, separate means for applying energy to each of said last mentioned means and means responsive to said beam segments, said means for controlling the deflection of said beam segments including a major electrode disposed centrally oi the sweep path or said beam and a plurality of minor electrodes disposed in sequential relation along the sweep path of each said beam segment.

6. The cathode ray tube of claim 5, wherein said minor electrodes are spaced from said major electrode so as to be a greater distance from the major electrode as its beam outlet end than at its beam inlet end to provide passage for the beam and its deflection therebetween.

'7. The cathode ray tube of claim 5, wherein said major electrode is at least partially irustoconical in shape.

8. The cathode ray tube of claim 5, wherein said major electrode is at least partially cylindrical in shape.

9. A cathode ray tube comprising: means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, means to divide the beam into a successive plurality of segments with respect to said sweep movement, a deflecting electrode arranged along the path of each said beam segments to control the radial deflection of that beam segment, separate means for applying energy to each or said electrodes, and means responsive to said beam segments having the form of an obtuse cone positioned axially pi said tube, the conical sides of which are substantially perpendicular to said beam segment as it is deflected around the tube.

10. In a beam tube having an envelope, means therein providing a source of electrons, means forming the electrons into a beam, means including electrodes arranged about the beam in space quadrature for deflecting the beam, and a target electrode, the combination of sets of deflecting electrodes positioned substantially in said certain deflected paths of the beam and an output electrode having elongated and tapered slots for passing the deflected beam positioned between said last mentioned deflecting electrode and the target electrode, said output electrode having a surface at which the beam arrives which is shaped to be substantially perpendicular to the beam in its diiferent deflected positions.

11. A beam tube according to claim 10, wherein the target electrode has a surface at which the beam arrives which is shaped to be substantially perpendicular to the beam in its diflferent deflected positions.

12. A beam tube according to claim 10, wherein the deflecting electrodes of the several sets comprise a frusto-conical common electrode and an electrode individual to its set, said last mentioned electrode being elongated and tapered and arranged along and in spaced relation to the curved surface of the common electrode.

13. A multichannel pulse modulator comprising means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, a plurality of signal channel input circuits, means associated with said input circuits to control deflection of the beam successively during its 15 sweep movement according to increment oi the l1 nput signal of said circuits, and beam responsive deans to provide pulses of energy modulated acording to the corresponding signal deflection of aid beam; said beam responsive means includng a shielding means having apertures therein hrough which said beam passes, said apertures cing so proportioned respecting length and readth and so positioned with respect to the notion of said beam to transmit the energy from he beam through each aperture successively in time space relationship substantially directly roportional to the amount of energy applied to aid means for deflecting said beam and said aprtures being so shaped that they transmit equal mounts of energy at all deflection positions of aid beam therealong. i

14. A multichannel pulse modulator comprisrig: means to produce a beam of electrons, deans to cause said beam to have a circular weep movement, means to divide the beam into successive plurality of segments with respect to aid sweep movement, a plurality of signal chan- ,el input circuits, means associated with said inut circuits to control deflection of the beam egments successively during their sweep moveient according to the increment of the input sigal of said circuits, means responsive to said eam segments, and shielding means positioned etween said beam responsive means and said leans to control deflection of said beam segients; said shielding means having long and narow arcuate apertur 3s therein corresponding to ach beam segment through which said beam egments pass, said apertures being shaped and ositioned to cover substantially the curved heoretical time spaced deflection line calculated compensate for the different circumferential weep velocities of said beam segments, so that nergy of each beam segment is transmitted sucessively to said beam responsive meansin time isplaced relationship directly proportional to the mount of energy applied to said deflecting elecrode whereby distortion of said proportion due to aid different velocities of said beam segments is revented.

15. A multichannel pulse modulator comprising leans to produce a beam of electrons, means to ause said beam to have a circular sweep movelent, means to divide the beam into a successive lurality of segments with respect to said sweep iovement, a plurality of signal channel input ircuits, means associated with each of said inut circuits to control deflection of said beam uccessively durin its sweep movement accordig to the increment of the input signal on said ircuits. beam responsive means, and a shielding means positioned between said beam res onsive leans and said means for deflecting said beam egments. said shielding means having apertures herein corresponding to each beam segment hrough which that beam segment passes, each f said apertures being long and narrow and disosed at an acute angle to the radius through he center of said tube and spaced slightly in the pposite direction of the sweep movement of said eam segment whereby the theoretical time paced deflection curved line for traverse by the rid of the beam segments is substantially brackted so that the entry from each said beam segients is transmitted successively to said beam esponsive means in a time displaced relationship ubstantially directly proportional to the amount f energy applied to said deflecting electrode and hereby produces pulses of energy modulated ac- 12 cording to the corresponding signal deflection of said beam segments.

16. In a multichannel pulse modulator, means to produce a beam of electrons, means to cause the beam to have a given sweep movement, channel commutating means for producing beam segments with respect to said sweep movement, a plurality of signal channel input circuits, means associated with said input circuits to control deflection of the beam segments successively during its sweep movement according to increment of the input signal of said-circuit, and beam responsive means to produce pulse of energy time modulated according to the corresponding signal deflections of said beam segments; said beam responsive means including means for presenting narrow target areas for impingement by electrons 01 said beam to produce current flow, the central portion of said areas being arranged at an arcuately disposed acute angle toward and to the direction of signal deflection of said beam, and the ends of said areas being arranged substantially parallel to the direction of said deflection.

17. A multichannel pulse modulator compris-- ing means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, a plurality of signal channel input circuits, means associated with said input circuits to control deflection of the beam successively during its sweep movement according to increment of the input signal of said circuit and beam responsive means to produce pulses of energy modulated according to the corresponding signal deflection of said beam; and shielding means positioned between said beam responsive means and said deflecting means, said shielding means having apertures therein through which said beam passes, said apertures being so proportioned respecting length and breadth and so positioned with respect to the motions of said beam to transmit the energy in the beam successively to said beam responsive means in a time displaced relationship substantially directly proportional to the amount of energy applied to said deflecting means; said deflecting means including a major electrode disposed centrally of the sweep path of said beam and a plurality of minor electrodes disposed in sequential relation along the sweep path of said beam spaced from said major electrode; and said beam responsive means having the shape of anobtuse cone positioned axially of said tube, the conical sides of which are substantially perpendicular to said beam as it is deflected around the tube. a

18. A multichannel pulse modulator comprising means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, a plurality of signal channel input circuits, means associated with said input circuits to control deflection 01' the beam successively during its sweep movement according to increments of the input signal of said circuits, and beam responsive means to produce pulses of energy modulated according to the corresponding signal deflection of said beam; said means for controlling signal deflection of the beam including a major electrode disposed centrally of the sweep path of said beam and a plurality of minor electrodes disposed in sequential relation along the sweep path of said beam and spaced from said major electrode so as to be a greater distance from the major electrode at its beam outlet end than at its beam inlet end to Provide passage for the beam and its deflection therebetween, and means for connecting said circuits each to one of said small electrodes.

19. A multichannel pulse modulator comprising means to produce a beam of electrodes, means to cause said beam to have a circular sweep movement, a plurality of signal channel input circuits, means associated with said input circuits to control deflection of the beam successively during its sweep movement according to increments of the input signal in such circuits, and beam responsive means comprising a shielding means and a beam responsive plate to produce pulses of energy modulated according to the corresponding signal deflection of said beam, both 01 said shielding means and said plate comprising obtuse cones positioned axially 01' said tube, the conical sides of which are substantially tangent to the beam as it is deflected around the tube.

20. A multichannel pulse modulator comprising means for producing a beam of electrons, means to cause said beam to have a circular sweep movement, a plurality of signal channel input circuits, means associated with said input circuits to control deflection oi the beam successively during its sweep movement according to increment of the input signal of said circuits, and beam responsive means to produce pulses of energy modulated according to the corresponding signal deflection oi said beam, said beam responsive means comprising an obtuse cone positioned axially of said tube, the conical sides of which are substantially tangent to said beam as it is deflected around the tube.

.21. A multichannel pulse modulator comprising means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, a plurality of signal channel input circuits, means associated with said input circuits to control deflection oi the beam successively during its sweep movement according to increment of input signal in such circuits, and beam responsive means comprising a shielding means and a beam responsive plate to produce pulses of energy modulated according to the corresponding signal deflection 01' said beam, said shielding means comprising an obtuse cone positioned axially of said tube, the conical sides of which are substantially perpendicular to the beam as it is deflected around the tube.

22. A cathode ray tube comprising: means'to produce a beam of electrons, means to cause said beam to have a circular sweep movement, means to divide the beam into a successive plurality of segments with respect to said sweep movement, a plurality of signal channel input circuits, means associated with said input circuits to control deflection of the beam successively during its sweep movement according to the increment or the input signal of said circuits, means responsive to said beam segments, shielding means positioned between said beam responsive means and said deflecting means; said shielding means having apertures therein through which said so positioned with respect to the motion of said beam segments to transmit energy of each beam segment successively to said beam responsive means in time displaced relationship successively directly proportional to the amount of energy applied to said deflecting electrodes; and said means for controlling the deflection of said beam segments including means to control the acceleration of the beam, and means responsive to the changes in acceleration of the beam to deflect the beam with respect to said beam responsive means.

23. A multichannel modulator comprising: means to produce a beam of electrons, means to cause said beam to have a circular sweep movement, means to divide the beam into a successive plurality of segments with respect to said sweep movement, a plurality of signal channel input circuits, means associated with said input circuit to control deflection of the beam successively during its sweep movement according to the increment of the input signal of said circuits, means responsive to said beam segments, and shielding means positioned between said beam responsive means and said deflecting means, said shielding means having long and narrow arcuate apertures therein corresponding to each beam segment through which said beam segments pass, said apertures being shaped and positioned to cover substantially the curved theoretical time shaped deflection line calculated to compensate for the different circumferential sweep velocities of said beam segments, so that the energy of each beam segment is transmitted successively to said beam responsive means in time displaced relationship directly proportional to the amount of energy applied to said deflecting means whereby distortion of said proportion due to said different velocities of said beam segments is prevented; and said deflecting means including means to control the acceleration of the beam, and means responsive to the changes in acceleration of the beam to deflect the beam with respect to said beam responsive means.

EMILE LABIN. DONALD D. GRIEG.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS 

